1. Field of the Invention
The present invention is related to an apparatus and method to achieve a constant sample rate for multiplexed signals with frame boundaries.
2. Related Art
In an example “Conventional” approach, a single digitizer (or other) resource can be shared among multiple video streams by placing an analog multiplexer between the analog video sources and the digitizer. The analog multiplexer is then switched (at the appropriate time), the digitizer is synchronized to the new video source, and a sample (field or frame) is grabbed. This sample is presented as the next sample for a logical stream associated with the specific video source. After each frame is grabbed, the sequence is repeated for the next (or in some specific cases, the same) source.
If there is a need to achieve a higher frame rate for a specific source, or sources, the order of switching, as specified by the index of each source, can be modified to provide a higher weighting to such source or sources.
A significant limitation of the “Conventional” approach is that it is not possible to specify a specific, pre-determined, frame rate for each logical stream (source). In some cases, such as video encoding, it is very important to allow the application to specify the frame rate, in order to get the best quality, predictable, results.